From: Amara Graps (amara@amara.com)
Date: Tue Sep 09 2003 - 10:41:25 MDT
"Kevin Freels" megaquark@hotmail.com <mailto:megaquark@hotmail.com>
>had questioned the breakage scenario and mentioned a possibility of:
>>Way bad idea. imagine a scenario where a space elevator were placed =
>>into GEO with an altitude of 36,000 km (22,369 miles).
It could be a bad idea for other reasons too (I didn't read this
thread, but GEO caught my eye)
Satellites break up in GEO regularly. These large pieces are
tracked and don't pose threats in general because their
filling factor in space is low. However drag is not a force
that can bring these objects down, so the GEO population is
only growing in time.
In addition, the smaller (<1cm) GEO debris population is not
known well because in-situ dust/debris detectors in GEO are
few/rare, remote sensing cannot detect the small particles,
and we don't have enough opportunities to bring back solar
panels and other surfaces of satellites to examine their
hypervelocity impact record.
People (including me) are using what we can to learn about the
debris/dust population in GEO, but there's not enough
data. What we've learned so far are rough flux numbers and it
appears that debris and natural micrometeoroid number
densities are about the same. The charges and velocities and
masses of the tiny particles in GEO are pretty uncertain
though. The GORID detector, twin of Ulysses' dust detector,
which piggybacked on a Russian telecommunications satellite
for 6 years, is likely our best data set for a while (it was
turned off one year ago). The data is being analyzed in detail
now.
I hope also those people that are looking at GEO for space
elevators are up to speed on their Earth's magnetosphere
physics.
GEO tends to skim the inner boundary of the plasma sheet, and
the radiation belts and ring current are located near GEO, as
well. During solar quiet times, the bodies orbiting at this
location are typically at dipolar-like field lines. During
large magnetic storms, the bodies orbiting at GEO are within
stretched field lines. It can be a very energetic place.
Amara
-- ******************************************************************** Amara Graps, PhD email: amara@amara.com Computational Physics vita: ftp://ftp.amara.com/pub/resume.txt Multiplex Answers URL: http://www.amara.com/ ******************************************************************** "What would you call the creation of the universe?" --Hobbes "The Horrendous Space Kablooie!" --Calvin
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